Zoonomia/II.A

ADDITION I.


 * At the end of the article Canities, in Class I. 2. 2. 11. please to add the following:

As mechanical injury from a percussion, or a wound, or a caustic, is liable to occasion the hair of the part to become grey; so I suspect the compression of parts against each other of some animals in the womb is liable to render the hair of those parts of a lighter colour; as seems often to occur in black cats and dogs. A small terrier bitch now stands by me, which is black on all those parts, which were external, when she was wrapped up in the uterus, teres atque rotunda; and those parts white, which were most constantly pressed together; and those parts tawny, which were generally but less constantly pressed together. Thus the hair of the back from the forehead to the end of the tail is black, as well as that of the sides, and external parts of the legs, both before and behind.

As in the uterus the chin of the whelp is bent down, and lies in contact with the fore part of the neck and breast; the tail is applied close against the division of the thighs behind; the inside of the hinder thighs are pressed close to the sides of the belly, all these parts have white hairs.

The fore-legs in the uterus lie on each side of the face; so that the feet cover part of the temples, and compress the prominent part of the upper eye-brows, but are so placed as to defend the eye-balls from pressure; it is curious to observe, that the hair of the sides of the face, and of the prominent upper eye-brows, are tawny, and of the inside of the feet and legs, which covered them; for as this posture admitted of more change in the latter weeks of gestation, the colour of these parts is not so far removed from black, as of those parts, where the contact or compression was more uniform.

Where this uterine compression of parts has not been so great as to render the hair white in other animals, it frequently happens, that the extremities of the body are white, as the feet, and noses, and tips of the ears of dogs and cats and horses, where the circulation is naturally weaker; whence it would seem, that the capillary glands, which form the hair, are impeded in the first instance by compression, and in the last by the debility of the circulation in them. See Class I. 1. 2. 15.

This day, August 8th, 1794, I have seen a negro, who was born (as he reports) of black parents, both father and mother, at Kingston in Jamaica, who has many large white blotches on the skin of his limbs and body; which I thought felt not so soft to the finger, as the black parts. He has a white divergent blaze from the summit of his nose to the vertex of his head; the upper part of which, where it extends on the hairy scalp, has thick curled hair, like the other part of his head, but quite white. By these marks I supposed him to be the same black, who is described, when only two years old, in the Transactions of the American Philosophical Society, Vol. II. page 292, where a female one is likewise described with nearly similar marks.

The joining of the frontal bones, and the bregma, having been later than that of the other sutures of the cranium, probably gave cause to the whiteness of the hair on these parts by delaying or impeding its growth.

ADDITION II.

The following extract from a letter of Dr. Beddoes on hydrocephalus internus, I esteem a valuable addition to the article on that subject at Class I. 2. 3. 12.


 * "Master L——, aged 9 years, became suddenly ill in the night about a week before I saw him. On the day before the attack, he had taken opening medicines, and had bathed afterwards. He had complained of violently acute pain in his head, shrieked frequently, ground his teeth hard, could not bear to have his head raised from the pillow, and was torpid or deaf. His tongue was white, pulse 110 in the evening and full. As yet the pupil of the eye was irritable, and he had no strabismus. He had been bled with leeches about the head, and blistered. I directed mercurial inunction, and calomel from 3 to 6 grains to be taken at first every six, and afterwards every three hours. This plan produced no sensible effect, and the patient died on the 18th day after the seizure. He had convulsion fits two days preceding his death, and the well-known symptoms of hydrocephalus internus all made their appearance. From what I had seen and read of this disease, I believed it to belong to inflammations, and at an earlier period I should be tempted to bleed as largely as for pneumonia. The fluid found after death in the ventricules of the brain I impute to debility of the absorbents induced by inflammation. My reasons are briefly these; 1. The acuteness of the pain. 2. The state of the pulse. In the above case for the first 9 or 10 days it did not exceed 110, and was full and strong.


 * 3. To find out whether any febrile alternations took place, Master L.'s feet were frequently felt, and they were found at times cold, and at other times of a dry heat. I have many times seen this disease, but the patients were too young, or too far advanced, to inform me, whether they had chillness succeeded by heat at its onset. 4. The disorders to which the young are more peculiarly liable afford a presumption, that hydrocephalus internus is an inflammatory disease; and this is confirmed by the regularity of the period, within which it finishes its course. And lastly, does it not happen more frequently than is suspected from external injury?


 * I have just now been well informed, that Dr. Rush has lately cured five out of six patients by copious bleedings. I relate here the reasons for an opinion without pretending to a discovery. Something like this doctrine may be found in certain modern publications, but it is delivered in that vague and diffuse style, which I trust your example will banish from medical literature."


 * Clifton, near Bristol,
 * July 28, 1795.

To this idea of Dr. Beddoes may be added, that the hydrocele generally succeeds an injury, and consequent inflammation of the bag, which contains it. And that other dropsies, which principally attend inebriates, are consequent to too great action of the mucous membranes by the stimulus of beer, wine, and spirits. And lastly, that as these cases of hydrocephalus end so fatally, a new mode of treating them is much to be desired, and deserves to be seriously attended to.

ADDITION III.

To be placed after the additional Note at the end of Vol. I. on this Subject.

Having reperused the ingenious Essay of Dr. Wells on Single Vision, and his additional observations in the Gentleman's Magazine on the apparent retrogression of objects in vertigo, I am induced to believe, that this apparent retrogression of objects is not always owing to the same cause.

When a person revolves with his eyes closed, till he becomes vertiginous, and then stands still without opening them, he seems for a while to go forward in the same direction. This hallucination of his ideas cannot be owing to ocular spectra, because, as Dr. Wells observes, no such can have been formed; but it must arise from a similar continuance or repetition of ideas belonging to the sense of touch, instead of to the sense of vision; and should therefore be called a tangible, not a visual, vertigo. In common language this belief of continuing to revolve for some time, after he stands still, when a person has turned round for a minute in the dark, would be called a deception of imagination.

Now at this time if he opens his eyes upon a gilt book, placed with other books on a shelf about the height of his eye, the gilt book seems to recede in the contrary direction; though his eyes are at this time kept quite still, as well as the gilt book. For if his eyes were not kept still, other books would fall on them in succession; which, when I repeatedly made the experiment, did not occur; and which thus evinces, that no motion of the eyes is the cause of the apparent retrocession of the gilt book. Why then does it happen?—Certainly from an hallucination of ideas, or in common language the deception of imagination.

The vertiginous person still imagines, that he continues to revolve forwards, after he has opened his eyes; and in consequence that the objects, which his eyes happen to fall upon, are revolving backward; as they would appear to do, if he was actually turning round with his eyes open. For he has been accustomed to observe the motions of bodies, whether apparent or real, so much more frequently by the eye than by the touch; that the present belief of his gyration, occasioned by the hallucinations of the sense of touch, is attended with ideas of such imagined motions of visible objects, as have always accompanied his former gyrations, and have thus been associated with the muscular actions and perceptions of touch, which occurred at the same time.

When the remains of colours are seen in the eye, they are termed ocular spectra; when remaining sounds are heard in the ear, they may be called auricular murmurs; but when the remaining motions, or ideas, of the sense of touch continue, as in this vertigo of a blindfolded person, they have acquired no name, but may be termed evanescent titillations, or tangible hallucinations.

Whence I conclude, that vertigo may have for its cause either the ocular spectra of the sense of vision, when a person revolves with his eyes open; or the auricular murmurs of the sense of hearing, if he is revolved near a cascade; or the evanescent titillations of the sense of touch, if he revolves blindfold. All these I should wish to call vanishing ideas, or sensual motions, of those organs of sense; which, ideas, or sensual motions, have lately been associated in a circle, and therefore for a time continue to be excited. And what are the ideas of colours, when they are excited by imagination or memory, but the repetition of finer ocular spectra? What the idea of sounds, but the repetition of finer auricular murmurs? And what the ideas of tangible objects, but the repetition of finer evanescent titillations?

The tangible, and the auricular, and the visual vertigo, are all perceived by many people for a day or two after long travelling in a boat or coach; the motions of the vessel, or vehicle, or of the surrounding objects, and the noise of the wheels and oars, occur at intervals of reverie, or at the commencement of sleep. See Sect. XX. 5. These ideas, or sensual motions, of sight, of hearing, and of touch, are succeeded by the same effects as the ocular spectra, the auricular murmurs, and the evanescent titillations above mentioned; that is, by a kind of vertigo, and cannot in that respect be distinguished from them. Which is a further confirmation of the truth of the doctrine delivered in Sect. III. of this work, that the colours remaining in the eyes, which are termed ocular spectra, are ideas, or sensual motions, belonging to the sense of vision, which for too long a time continue their activity.

ADDITION IV.

A correspondent acquaints me, that he finds difficulty in understanding how the convulsions of the limbs in epilepsy can be induced by voluntary exertions. This I suspect first to have arisen from the double meaning of the words "involuntary motions;" which are sometimes used for those motions, which are performed without the interference of volition, as the pulsations of the heart and arteries; and at other times for those actions, which occur, where two counter volitions oppose each other, and the stronger prevails; as in endeavouring to suppress laughter, and to stop the shudderings, when exposed to cold. Thus when the poet writes,

———video meliora, proboque, Deteriora sequor.——

The stronger volition actuates the system, but not without the counteraction of unavailing smaller ones; which constitute deliberation.

A second difficulty may have arisen from the confined use of the words "to will," which in common discourse generally mean to choose after deliberation; and hence our will or volition is supposed to be always in our own power. But the will or voluntary power, acts always from motive, as explained in Sect. XXXIV. 1. and in Class IV. 1. 3. 2. and III. 2. 1. 12. which motive can frequently be examined previous to action, and balanced against opposite motives, which is called deliberation; at other times the motive is so powerful as immediately to excite the sensorial power of volition into action, without a previous balancing of opposite motives, or counter volitions. The former of these volitions is exercised in the common purposes of life, and the latter in the exertions of epilepsy and insanity.

It is difficult to think without words, which however all those must do, who discover new truths by reasoning; and still more difficult, when the words in common use deceive us by their twofold meanings, or by the inaccuracy of the ideas, which they suggest.

ADDITION V.

I feel myself much obliged by the accurate attention given to the first volume of Zoonomia, and by the ingenious criticisms bestowed on it, by the learned writers of that article both in the Analytical and English Reviews. Some circumstances, in which their sentiments do not accord with those expressed in the work, I intend to reconsider, and to explain further at some future time. One thing, in which both these gentlemen seem to dissent from me, I shall now mention, it is concerning the manner, in which we acquire the idea of figure; a circumstance of great importance in the knowledge of our intellect, as it shews the cause of the accuracy of our ideas of motion, time, space, number, and of the mathematical sciences, which are concerned in the mensurations or proportions of figure.

This I imagine may have in part arisen from the prepossession, which has almost universally prevailed, that ideas are immaterial beings, and therefore possess no properties in common with solid matter. Which I suppose to be a fanciful hypothesis, like the stories of ghosts and apparitions, which have so long amused, and still amuse, the credulous without any foundation in nature.

The existence of our own bodies, and of their solidity, and of their figure, and of their motions, is taken for granted in my account of ideas; because the ideas themselves are believed to consist of motions or configurations of solid fibres; and the question now proposed is, how we become acquainted with the figures of bodies external to our organs of sense? Which I can only repeat from what is mentioned in Sect. XIV. 2. 2. that if part of an organ of sense be stimulated into action, as of the sense of touch, that part so stimulated into action must possess figure, which must be similar to the figure of the body, which stimulates it.

Another previous prepossession of the mind, which may have rendered the manner of our acquiring the knowledge of figure less intelligible, may have arisen from the common opinion of the perceiving faculty residing in the head; whereas our daily experience shews, that our perception (which consists of an idea, and of the pleasure or pain it occasions) exists principally in the organ of sense, which is stimulated into action; as every one, who burns his finger in the candle, must be bold to deny.

When an ivory triangle is pressed on the palm of the hand, the figure of the surface of the part of the organ of touch thus compressed is a triangle, resembling in figure the figure of the external body, which compresses it. The action of the stimulated fibres, which constitute the idea of hardness and of figure, remains in this part of the sensorium, which forms the sense of touch; but the sensorial motion, which constitutes pleasure or pain, and which is excited in consequence of these fibrous motions of the organ of sense, is propagated to the central parts of the sensorium, or to the whole of it; though this generally occurs in less degree of energy, than it exists in the stimulated organ of sense; as in the instance above mentioned of burning a finger in the candle.

Some, who have espoused the doctrine of the immateriality of ideas, have seriously doubted the existence of a material world, with which only our senses acquaint us; and yet have assented to the existence of spirit, with which our senses cannot acquaint us; and have finally allowed, that all our knowledge is derived through the medium of our senses! They forget, that if the spirit of animation had no properties in common with matter, it could neither affect nor be affected by the material body. But the knowledge of our own material existence being granted, which I suspect few rational persons will seriously deny, the existence of a material external world follows in course; as our perceptions, when we are awake and not insane, are distinguished from those excited by sensation, as in our dreams, and from those excited by volition or by association as in insanity and reverie, by the power we have of comparing the present perceptions of one sense with those of another, as explained in Sect. XIV. 2. 5. And also by comparing the tribes of ideas, which the symbols of pictures, or of languages, suggest to us, by intuitive analogy with our previous experience, that is, with the common course of nature. See Class III. 2. 2. 3. on Credulity.

ADDITION VI.

Please to add the following in page 14, after line 20

Cold and hot Fit.

As the torpor, with which a fit of fever commences, is sometimes owing to defect of stimulus, as in going into the cold-bath; and sometimes to a previous exhaustion of the sensorial power by the action of some violent stimulus, as after coming out of a hot room into cold air; a longer time must elapse, before there can be a sufficient accumulation of sensorial power to produce a hot fit in one case than in the other. Because in the latter case the quantity of sensorial power previously expended must be supplied, before an accumulation can begin.

The cold paroxysm commences, when the torpor of a part becomes so great, and its motions in consequence so slow or feeble, as not to excite the sensorial power of association; which in health contributes to move the rest of the system, which is catenated with it. And the hot fit commences by the accumulation of the sensorial power of irritation of the part first affected, either so as to counteract its deficient stimulus, or its previous waste of sensorial power; and it becomes general by the accumulation of the sensorial power of association; which is excited by the renovated actions of the part first affected; or becomes so great as to overbalance the deficient excitement of it. On all these accounts the hot fit cannot be supposed to bear any proportion to the cold one in length of time, though the latter may be the consequence of the former. See Suppl. I. 16. 8.

ADDITION VII.

To be added at the end of the Species Sudor Calidus, in Class I. 1. 2. 3.

When the heat of the body in weak patients in fevers is increased by the stimulus of the points of flannel, a greater consequent debility succeeds, than when it is produced by the warmth of fire; as in the former the heat is in part owing to the increased activity of the skin, and consequent expenditure of sensorial power; whereas in the latter case it is in part owing to the influx of the fluid matter of heat.

So the warmth produced by equitation, or by rubbing the body and limbs with a smooth brush or hand, as is done after bathing in some parts of the East, does not expend nearly so much sensorial power, as when the warmth is produced by the locomotion of the whole weight of the body by muscular action, as in walking, or running, or swimming. Whence the warmth of a fire is to be preferred to flannel shirts for weak people, and the agitation of a horse to exercise on foot. And I suppose those, who are unfortunately lost in snow, who are on foot, are liable to perish sooner by being exhausted by their muscular exertions; and might frequently preserve themselves by lying on the ground, and covering themselves with snow, before they were too much exhausted by fatigue. See Botan. Garden, Vol. II. the note on Barometz.

ADDITION VIII.

To be added to Class II. 1. 6. 16.

A very interesting account of the puerperal fever, which was epidemic at Aberdeen, has been lately published by Dr. Alexander Gordon. (Robinson, London.) In several dissections of those, who died of this disease, purulent matter was found in the cavity of the abdomen; which he ascribes to an erysipelatous inflammation of the peritonæum, as its principal seat, and of its productions, as the omentum, mesentery, and peritonæal coat of the intestines.

He believes, that it was infectious, and that the contagion was always carried by the accoucheur or the nurse from one lying-in woman to another.

The disease began with violent unremitting pain of the abdomen on the day of delivery, or the next day, with shuddering, and very quick pulse, often 140 in a minute. In this situation, if he saw the patient within 12 or 24 hours of her seizure, he took away from 16 to 24 ounces of blood, which was always sizy. He then immediately gave a cathartic consisting of three grains of calomel, and 40 grains of powder of jalap. After this had operated, he gave an opiate at night; and continued the purging and the opiate for several days.

He asserts, that almost all those, whom he was permitted to treat in this manner early in the disease, recovered to the number of 50; and that almost all the rest died. But that when two or three days were elapsed, the patient became too weak for this method; and the matter was already formed, which destroyed them. Except that he saw two patients, who recovered after discharging a large quantity of matter at the navel. And a few, who were relieved by the appearance of external erysipelas on the extremities.

This disease, consisting of an erysipelatous inflammation, may occasion the great debility sooner to occur than in inflammation of the uterus; which latter is neither erysipelatous, I suppose, nor contagious. And the success of Dr. Gordon's practice seems to correspond with that of Dr. Rush in the contagious fever or plague at Philadelphia; which appeared to be much assisted by early evacuations. One case I saw some time ago, where violent unceasing pain of the whole abdomen occurred a few hours after delivery, with quick pulse; which ceased after the patient had twice lost about eight ounces of blood, and had taken a moderate cathartic with calomel.

This case induces me to think, that it might be safer and equally efficacious, to take less blood at first, than Dr. Gordon mentions, and to repeat the operation in a few hours, if the continuance of the symptoms should require it. And the same in respect to the cathartic, which might perhaps be given in less quantity, and repeated every two or three hours.

Nor should I wish to give an opiate after the first venesection and cathartic; as I suspect that this might be injurious, except those evacuations had emptied the vessels so much, that the stimulus of the opiate should act only by increasing the absorption of the new vessels or fluids produced on the surfaces of the inflamed membranes. In other inflammations of the bowels, and in acute rheumatism, I have seen the disease much prolonged, and I believe sometimes rendered fatal, by the too early administration of opiates, either along with cathartics, or at their intervals; while a small dose of opium given after sufficient evacuations produces absorption only by its stimulus, and much contributes to the cure of the patient. We may have visible testimony of this effect of opium, when a solution of it is put into an inflamed eye; if it be thus used previous to sufficient evacuation, it increases the inflammation; if it be used after sufficient evacuation, it increases absorption only, and clears the eye in a very small time.

I cannot omit observing, from considering these circumstances, how unwise is the common practice of giving an opiate to every woman immediately after her delivery, which must often have been of dangerous consequence.